Added -crfl attribute for DiffFormatterReflowTest test data

The test data is expected to have unix new lines by tests, but it
is converted to crlf on Windows platform (with msys git). As result
DiffFormatterReflowTest tests fail. To prevent this problem,
crlf conversion is disbled for test data related to that test.

Bug: 295077
Change-Id: I67d3ed543fcc38647041896146de12b1781ec6be
Signed-off-by: Constantine Plotnikov <constantine.plotnikov@gmail.com>

org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/.gitattributes

@@ -0,0 +1,3 @@
+*.patch -crlf
+*Image -crlf
+*.out -crlf